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    <meta charset="UTF-8">
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    <title>Document</title>
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<body>
    <script>
        class Father {
            say() {
                return ('爸爸');
            }
        }
        class Son extends Father {
            say() {
                //用super调用父类的普通函数
                console.log(super.say() + '我是儿子');
            }
        }
        var son = new Son();
        //调用普通函数是就近原则，先查看子类有没有函数
        son.say();
    </script>
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